Variable 'prefix' not set, Debian 8.6.0 installer boot failure.
 

Hi. I'm not really one for introductions on forums, and I'm really sorry if this is in the wrong forum.

Anyway, let's start trying to describe this. By the way, Windows Vista is installed on the laptop. AMD64, no UEFI or GPT although my laptop can do both. I've got a Debian 8.6 install option already set up, but it starts with a "Try hd(0,0) NTFS5 error: variable prefix not set," before going on a second later to mount errors. All the possible drives—3 USB and one HDD—can't mount due to an invalid argument, and then can't unmount because it wasn't mounted in the first place. I've got a feeling this is interfering with Vista since USB devices stop working. Then, sometimes it flashes green lines, bamds, and noise for a split second each, before simply going to an eternal fully black screen. Which is around the time I restart into Windows Vista to see if I can fix something. I've so far fixed a deprecated vga:780 tag, but nothing else, even after a long while of searching. Maybe I wasn't that thorough, though. Most of the results seem to be for Wubi Ubuntu and after it's already been installed.

Specs, as Windows Vista sees them:
Vista Home Premium, SP2.
Acer Aspire ES1-711
x64 based (MBR & BIOS laptop, although it came originally with GPT and UEFI.)
Processor: Intel Pentium N3540 @2.16GHz, 2159 Mhz, 4 cores, 4 logical processors.
BIOS version, date: Insyde Corp, 1.04, 9/12/2014
RAM: 4.0 GB
Total physical memory: 3.89 GB
Of that, available: 3.14 GB
Virtual memory total: 7.95 GB
Of that, available: 7.18 GB
CD-ROM device: HL-DT-ST DVDRAM GUC0N ATA device
Display: Standard VGA at 1600x900, really Intel HD "Bay Trail"
Keyboard: PS/2 keyboard (Laptop keyboard with working touchpad),
USB: Pentium N-types,
Drive: Uncompressed 465.76 GB MBR/NTFS disk, 395.58 GB free.

I wonder what that means. Is this some sort of Wubi install you are attempting?

What exactly does that mean? Do you have the Debian DVD in the drive or a flash drive plugged in?

If you have Vista installed, I expect it is on sda1 (hd0,0) and NTFS is a windows filesystem.

How do you try to mount the various partitions you say won't mount?

You're confusing thins with your reference to WUBI. What does that have to do with your attempt to install Debian? WUBI is "windows ubuntu installer" and is used strictly with Ubuntu and some of it's derivatives which Debian is certainly not. Although you may get wubi to work (if that's what you are trying to do?) it hasn't been supported by the Ubuntu developers for several years.

Sorry for the wait, I haven't had internet. No, I used—I think it was—win32_loader to make an installer option in the Windows boot manager to install it.

I only manage to select the Debian install option in the boot manager, it does all the rest. If you want, I'll see if I can get a video up. About WUBI, I waa saying that the only posts I found about the try error were for already installed WUBI, although I forgot to mention a handful of Mint users had it, but I didn't see anything for before the installer starts.